From 15 complaints over the previous five years, Los Angeles County sees 60 just in December. Recent publicity over a Chino Hills case may have spurred the increase.

Los Angeles County residents are growing weary of maternity hotels in their neighborhoods, filing 60 complaints in the last month alone, according to a report by the county Planning Department.

The surge, from just 15 complaints spread over the previous five years, appears related to media coverage of a Chino Hills case in early December, which may have encouraged people to come forward.

The facilities are typically set up in single-family homes in quiet residential neighborhoods, particularly in the San Gabriel Valley. The Chino Hills site, which shut down after the city sued its owners, had been illegally subdivided into 17 bedrooms and 17 bathrooms, according to city officials. Neighbors complained of frequent comings and goings, and an overloaded septic tank caused a massive sewage spill.

County officials investigating the recent complaints determined that all but one of the 60 came from areas where boardinghouses are not allowed. Although the report does not specify locations, officials familiar with the investigation said many of the complaints came from Rowland Heights and Hacienda Heights.

The Jan. 14 report, commissioned by the county Board of Supervisors, outlines a plan to step up enforcement by involving other agencies, such as the county Health and Fire Departments.

So-called birth tourism is a booming industry, fueled by women from Asia who travel to the United States while pregnant. They live at boarding facilities for several months before giving birth, accumulating bills of as much as $20,000 by the time they return home with their American citizen babies.

The facilities in the San Gabriel Valley cater to Chinese and Taiwanese mothers, while women from South Korea patronize maternity hotels in Los Angeles' Koreatown.

The practice does not violate federal immigration laws, but local governments can crack down on the hotels for zoning or building code violations.

Supervisor Don Knabe, whose district includes parts of the eastern San Gabriel Valley, wants to develop a county ordinance specific to maternity hotels, with the goal of shutting them all down.

"They're a moneymaking machine. They're totally unsafe," Knabe said. "It's so obvious that they jeopardize not only the health of the baby, but the mother as well."

Planning officials are already conducting joint inspections with colleagues at the Public Works and Child and Family Services departments, according to the report. Cases have been referred to the state tax board and Employment Development Department because of allegations involving tax evasion and fraud.

The report describes the difficulties of inspecting the facilities. Often, occupants do not come to the door. When they do, they often claim not to speak English and don't allow inspectors to enter. The hotels do not display any signs, and their exteriors are generally well-maintained, the report said, making it hard to prove that anything illegal is going on inside.

The Planning Department will try to include a Mandarin or Cantonese translator on its inspection teams, the report said.

If called to an alleged maternity hotel, Child and Family Services investigators would look for any signs of child abuse or neglect, said Neil Zanville, a department spokesman. Reports that newborn babies are crowded into makeshift nurseries would be cause for concern, he said.

"Having too many kids in one room poses an inherent health risk," Zanville said. "We'd not only ask about sleeping arrangements, we'd ask, 'Has this baby been seen by a doctor? Has it had its shots?' "